DbHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
using System.Collections;
namespace XXX
{
    public class DbHelper
    {
        private readonly string connString = ConfigurationManager.ConnectionStrings["sqlConnection"].ConnectionString;
        private static DbHelper dbhelper;
        private DbHelper() { }

        public static DbHelper Instance()
        {
            if (dbhelper == null)
                return dbhelper = new DbHelper();
            return dbhelper;
        }

        /// <summary>
        /// 返回connection对象 
        /// </summary>
        /// <returns></returns>
        public SqlConnection ReturnConn()
        {
            SqlConnection Conn = new SqlConnection(connString);
            Conn.Open();
            return Conn;
        }
        /// <summary>
        /// 断开connection
        /// </summary>
        /// <param name="Conn"></param>
        public void Dispose(SqlConnection Conn)
        {
            if (Conn != null)
            {
                Conn.Close();
                Conn.Dispose();
            }
            GC.Collect();
        }

        /// <summary>
        /// 运行SQL语句,返回受影响行数
        /// </summary>
        /// <param name="SQL"></param>
        public int ExecSql(string SQL)
        {
            SqlConnection Conn;
            Conn = ReturnConn();
            SqlCommand Cmd;
            Cmd = CreateCmd(SQL, Conn);
            int rows = 0;
            try
            {
                rows = Cmd.ExecuteNonQuery();
            }
            catch
            {
                throw new Exception(SQL);
            }
            Dispose(Conn);
            return rows;
        }

        /// <summary>
        /// 运行SQL语句返回DataReader
        /// </summary>
        /// <param name="SQL"></param>
        /// <returns>SqlDataReader对象.</returns>
        public SqlDataReader ExecSqlGetReader(string SQL)
        {
            SqlConnection Conn = ReturnConn();
            SqlCommand Cmd;
            Cmd = CreateCmd(SQL, Conn);
            SqlDataReader Dr;
            try
            {
                Dr = Cmd.ExecuteReader(CommandBehavior.Default);
            }
            catch
            {
                throw new Exception(SQL);
            }
            return Dr;
        }


        /// <summary>
        /// 运行SQL语句,返回DataSet对象
        /// </summary>
        /// <param name="procName">SQL语句</param>
        /// <param name="prams">DataSet对象</param>
        public DataSet ExecSqlGetDs(string SQL)
        {
            return ExecSql(SQL,null);
        }

        /// <summary>
        /// 检验是否存在数据
        /// </summary>
        /// <returns></returns>
        public bool ExistDate(string SQL)
        {
            SqlConnection Conn = ReturnConn();
            SqlDataReader Dr;
            Dr = CreateCmd(SQL, Conn).ExecuteReader();
            if (Dr.Read())
            {
                Dispose(Conn);
                return true;
            }
            else
            {
                Dispose(Conn);
                return false;
            }
        }

        /// <summary>
        /// 执行多条SQL语句，实现数据库事务。
        /// </summary>
        /// <param name="SQLStringList">多条SQL语句</param>
        public void ExecSqlTran(ArrayList SQLStringList)
        {
            using (SqlConnection conn = ReturnConn())
            {
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                SqlTransaction tx = conn.BeginTransaction();
                cmd.Transaction = tx;
                try
                {
                    for (int n = 0; n < SQLStringList.Count; n++)
                    {
                        string strsql = SQLStringList[n].ToString();
                        if (strsql.Trim().Length > 1)
                        {
                            cmd.CommandText = strsql;
                            cmd.ExecuteNonQuery();
                        }
                    }
                    tx.Commit();
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    tx.Rollback();
                    throw new Exception(E.Message);
                }
            }
        }


        /// <summary>
        /// 返回SQL语句执行结果的第一行第一列
        /// </summary>
        /// <returns>object对象</returns>
        public object ReturnValue(string SQL)
        {
            return ReturnValue(SQL,0);
        }

        /// <summary>
        /// 返回SQL语句第一行,第ColumnI列 从0开始
        /// </summary>
        /// <returns>字符串</returns>
        public object ReturnValue(string SQL, int ColumnI)
        {
            object result = null;
            try
            {
                SqlDataReader Dr = ExecSqlGetReader(SQL);
                if (Dr.Read())
                {
                    result = Dr[ColumnI];
                }
            }
            catch
            {
                throw new Exception(SQL);
            }
            
            return result;
        }

        /// <summary>
        /// 执行查询语句，返回DataSet
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <param name="cmdParms">SQL语句用到的参数数组或null</param>
        /// <returns>DataSet</returns>
        public DataSet ExecSql(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlConnection connection = ReturnConn())
            {
                SqlCommand cmd = CreateCmd(SQLString, cmdParms, CommandType.Text);
                
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                {
                    DataSet ds = new DataSet();
                    try
                    {
                        da.Fill(ds);
                        cmd.Parameters.Clear();
                    }
                    catch (System.Data.SqlClient.SqlException ex)
                    {
                        throw new Exception(ex.Message);
                    }
                    return ds;
                }
            }
        }

       

        /// <summary>
        /// 运行存储过程,返回dataset
        /// </summary>
        /// <param name="procName">存储过程名.</param>
        /// <param name="prams">存储过程入参数组.</param>
        /// <returns>dataset对象.</returns>
        public DataSet ExecProc(string procName, SqlParameter[] prams)
        {
            SqlCommand Cmd = CreateCmd(procName, prams,CommandType.StoredProcedure);
            DataSet Ds = new DataSet();
            SqlDataAdapter Da = new SqlDataAdapter(Cmd);
            try
            {
                Da.Fill(Ds);
            }
            catch (Exception Ex)
            {
                throw Ex;
            }
            return Ds;
        }


        /// <summary>
        /// 生成一个存储过程使用的sqlcommand.
        /// </summary>
        /// <param name="procName">存储过程名.</param>
        /// <param name="prams">存储过程入参数组.</param>
        /// <param name="type">sql的类型</param>
        /// <returns>sqlcommand对象.</returns>
        public SqlCommand CreateCmd(string Sql, SqlParameter[] prams,CommandType type)
        {
            SqlConnection Conn;
            Conn = ReturnConn();
            SqlCommand Cmd = new SqlCommand(Sql, Conn);
            Cmd.CommandType = type;
            if (prams != null)
            {
                foreach (SqlParameter parameter in prams)
                {
                    if (parameter != null)
                    {
                        Cmd.Parameters.Add(parameter);
                    }
                }
            }
            return Cmd;
        }

        /// <summary>
        /// 生成Command对象
        /// </summary>
        /// <param name="SQL"></param>
        /// <param name="Conn"></param>
        /// <returns></returns>
        public SqlCommand CreateCmd(string SQL, SqlConnection Conn)
        {
            SqlCommand Cmd;
            Cmd = new SqlCommand(SQL, Conn);
            return Cmd;
        }
    }
}

未完全测试,持续更新中...